Observing Log for Night 111  (Jun 19 1997  UT)

Observer: E. Howard

Weather Conditions: before sunset - a few clouds toward eastern horizon, 
                                    otherwise clear. 
                    20:56- clear. Some stars twinkling. Moon is very bright. 
                    23:02- A couple of tiny cumulus? clouds have appeared to
                           the north and east. Clear where we are pointing.
                    23:08- clouds drifting more overhead. Looks like they 
                           are forming above us, due to the mountain. They
                           are relativly isolated small thin puffy clouds
                    23:27- Most of the clouds are gone. One small cloud 
                           remains to the north. A couple of clouds are
                           visable toward the southern horizon, otherwise
                           clear 
                    23:48- Clouds have dissapated. A few clouds remain on
                           distant southern horizon.
                    00:29- Clouds are forming again to the south east. Thin
                           relatively isolated, puffy clouds.
                    00:44- Small puffy clouds remain. Most lie to the 
                           southeast, but a few are scattered around. 
                    01:03- A few small puffy clouds scattered about.
                    02:07- Clouds have mostly dissapated.
                    02:35- Clear.
                    04:27- At end, a few clouds toward south-western horizon, 
                           otherwise clear.

Eyeball quality estimates: 001- before sunset- photometric, but stars twinkling
                           048- probably photometric where we are pointing, but
                                small clouds to east and north.
                           049- marginally photometric at best.
                           052- marginally photometric
                           055- probably photometric
                           063- marginally photometric
                           066- likely not photometric `photometric between
                                the clouds'
                           084- marginally photometric
                           096- photometric.
                           end- marginally photometric.
Notes:

MST   Scan    Comment
18:20 001     tt=19.1 t=16.1 darks
19:33 002     flats 14h +31
20:20 008     tt=17.9 t=15.5 humid=0.23 bkg=700,3550,3550
              seeing looks pretty bad.
20:30 011     camera hangup, restart
20:35 014     tt=18.3 t=18.7 humid=0.21 bkg=500,2850,3300
20:44 020     tt=18.2 t=19.0 humid=0.21 bkg=510,3110,3357
20:52 021     strange circle seen yesterday was back today. It was a
              bright circle at K, a dark circle at H and it tracked in
              a strange pattern sort of diagonally across both arrays, 
              clearly a reflection of some sort. Seen around frames 15-20.
21:00 022     seeing looks better, but probably still not great. OH is
              fluxuating more +/- 100 at H.
21:20 025     tt=19.2 t=19.3 humid=0.22 bkg=500,3800,3675
21:41 028     tt=19.5 t=19.5 humid=0.22 bkg=380,3075,3500
22:22 034     tt=19.6 t=19.6 humid=0.22 bkg=450,3800,3750
22:24 034     camera hangup, restart.
22:31 038     another camera hangup, restart.
22:36 040                               bkg=550,4075,3900
22:58 048     tt=20.2 t=20.1 humid=0.20 bkg=340,2925,3525
23:08 049     clouds may be drifting close soon, watch for sudden bkg changes.
23:17 050                               bkg=380,3425,3675
00:05 057                               bkg=290,2750,3525
00:23 060     tt=20.3 t=20.3 humid=0.19 bkg=300,3000,3650
00:27 063     a few clouds have formed to the southeast (clear where we are
              pointing)
00:33 066     seeing looks pretty bad. Clouds lie just below where we are
              pointing. 
00:41 072     tt=20.4 t=20.3 humid=0.15 bkg=225,2150,3350. Small puffy
              clouds remain.
01:45 081                               bkg=175,1725,3375
02:05 084     tt=20.5 t=20.0 humid=0.16 bkg=200,2075,3350
              clouds have mostly disapated, 1 or 2 small clouds remain
              toward the southeast.
02:20 086     tt=20.3 t=19.3            bkg=250,2300,3450
02:30 092     `asteroid'
03:15 103     Strange K-band reflections.
03:34 106     tt=19.6 t=18.9 humid=0.22 bkg=125,1300,2900
04:02 110     tt=19.3 t=18.7 humid=0.23 bkg=50,975,2775
04:50         fill dewar